TYPO3 Core

With security advisory https://typo3.org/security/advisory/TYPO3-CORE-SA-2020-004 new BlockSerializationTrait has been introduced blocking serialization and deserialization for a couple of classes (see advisory for details). Since this cause a couple of side-effects for valid use-cases, the restriction on serialize() is removed - which is fine from a security point of view.

Possible use case:
Some system state has to be persisted for documentation purposes, which needs a working serialization. De-serialization is not needed in such cases.
Reported by Gernot Leitgab in https://typo3.slack.com/archives/C0K5MU94J/p1589366052028100